The Chinese have built a large number of 140 foot long, 225 ton vessels (perhaps 100) using a relatively exotic hull form, and there is a suggestion that they may start offering export derivatives of the hull for maritime policing.
You can see the type in motion here. Click on “Type 022 (Houbei Class).” The video is 2m 11s long. (What is the device at the stern seen at 1:51 in the video? dipping sonar?)
There is more information describing the technology and the origin of the design here.
There is an interesting, but unconventional, view of how these ships may be used here.
There are some still pictures here.
For those of you who may be US Naval Institute members, there is an article on the class here. Unfortunately, it is only accessible to members.